This application addresses the need for selective non-toxic for acne. Excessive 5alpha-reductase activity is found in acne vulgaris as well as androgenic alopecia (male pattern baldness). Numerous side effects occur from current treatments of these diseases both of which originate in the pilosebaceous unit. We have developed a selective, effective, topically applied 5alpha-reductase inhibitor to modify pathological processes in the pilosebaceous unit. For example, toward this goal, we have previously developed a selective topical liposome hair follicle targeting technology fo r genes and other large and small molecules. The present application will focus on our recent observation that the 5-alpha- reductase inhibitor N, N-diethyl-4-methyl-3-oxo-4-aza-5alpha- androstane-17beta-carboxamide (4-MA) incorporated into liposomes selectively induces apoptosis and inhibits growth of the dihydrotestosterone (DHT)-dependent hamster flank organ sebaceous gland. With regard to selectivity, when non-liposomal 4-MA was topically applied, the selective efficacy was lost resulting in the on- targeted contralateral gland being affected. With regards to safety, liposome 4-MA did not significantly affect prostate weight, T/DHT ratios or body weight gain compared to controls indicating safety as well as efficacy of topical application of liposome 4-MA. We proposed here to develop topical liposomal 4-MAS as an anti-acne agent. The Specific Aims of this application are as follows: 1) Optimize efficacy of topical liposomal 4-MA to selectively induce apoptosis of sebaceous glands of male hamsters; 2) Determine pharmacokinetics of topical liposomal 4- MA to hair follicles of human scalp grafted into SCID mice and in the hamster sebaceous gland; 5) Determine safety of effective doses of liposomal-4-MA by detection of changes in DHT/T blood ratios in treated animals. In Phase II, selective efficacy and safety studies will be conducted on larger animals in order to enable liposomal 4-MA to enter the clinic as an anti-acne therapeutic. PROPOSED COMMERCIAL APPLICATIONS: Liposomal 4-MA will be developed as a topical selectively targeted therapeutic for acne for which they should be a very market.